Underwater compressed-gas gun

ABSTRACT

Compressed-gas gun for projecting a spear under water, consisting of a compressed-air tank and a gun body formed of two tubes assembled end to end, one located at the front which constitutes the barrel and the other which contains an elastic sleeve serving as impervious joint between a compressed-gas reserve chamber and the barrel. The elastic sleeve and body define a further chamber which is cooperative with a trigger to selectively release the spear. Pressure on the spear by the elastic sleeve holds the spear tight before firing, but deformation of the sleeve away from the spear during firing permits the spear to be released.

. 22 Filed:

[21 Appl.No.: 57,184

United States Patent [191 Barjavel UNDERWATER COMPRESSED-GAS GUN [76]Inventor: Jenn- Barjavel, 70 Avenue Gernuschi, Nice, France July 22,1970 [30] Foreign Application Priority Data [451 May 29, 1973 1,122,8731/1962 Germany ..l24/1l Primary ExaminerRichard C. Pinkham AssistantExaminer-R. T. Stouffer Att0rneyWard, McElhannon, Brooks & Fitzpatrick[5 7] ABSTRACT Compressed-gas gun for projecting a spear under water,consisting of a compressed-air tank and a gun body formed of two tubesassembled end to end, one located at the front which constitutes thebarrel and the other which contains an elastic sleeve serving asimpervious joint between a compressed-gas reserve chamber and thebarrel. The elastic sleeve and body define a further chamber which iscooperative with a trigger to selectively release the spear. Pressure onthe spear by the elastic sleeve holds the spear tight before firing, butdeformation of the sleeve away from the spear during firing permits thespear to be released.

6 Claims, 2 Drawing Figures 1 UNDERWATER COMPRESSED-GAS GUN The objectof the present invention is a compressedgas gun for propelling a spearunder water.

Underwater compressed-gas guns are known which are composed of a gastank provided with a valve and a gun body in which the spear is placed,said body being are placed around the barrel.

The other tube, of larger diameter, contains, from the rear to thefront, a thrust chamber in which the rear end of the spear is contained;a compressed-gas reserve chamber and an elastic sleeve the insidediameter of which is slightly less than the outside diameter of thespear. This sleeve, together with the second tube, defines an annularspace which communicates, via a conduit equipped with a valve, with thecompressed-gas tank and, via another conduit equipped with a valve, withthe outside.

The opening of the said valve can be controlled by the hunter by meansof a trigger. The valve is calibrated and opens if the gas pressure inthe gun exceeds a limit value. The said annular enclosure communicateswith the compressed-gas reserve chamber located immediately to the rearof the elastic sleeve by orifices equipped with nonreturn valves.

The gun comprises at the rear a thrust chamber separated from thereserve chamber by a tight packing. This thrust chamber communicateswith the outside through an orifice provided with a floating valve thehead of which is located on the inside of the thrust chamber.

The rear end of the gun is closed by a threaded plug which is screwedonto the tube. This plug is pierced throughout by at least one channelwhich communicates with the orifice equipped with the said floatingvalve. Within the plug there is arranged a cavity in which the guide rodof the floating valve slides. When the hunter screws this plug insufficiently, the rod of the valve presses against the rear part of thesaid cavity or to a shoulder in such a manner that the valve is lockedin open position. This is the safety position.

FIG. 1 is a cross-section through a gun in accordance with theinvention.

FIG. 2 is a cross-section on a larger scale through different parts ofFIG. 1. r

A gun in accordance with the invention comprises a compressed-gas tank 11 equipped with a valve 10. The gun barrel is composed at the front of atube 1 the inside diameter of which is slightly greater than the outsidediameter of the spear 2. 7

Around the front end of the barrel there are placed a slide 3 and a stop3a which is fastened to the barrel. The slide 3, upon moving forward,strikes against the ring 4 of the spear and causes the ejection thereof.

The rear part of the gun is formed of a second tube 5 the diameter ofwhich is greater than that of the tube 1.

Within the tube 5 there is arranged, at the front, a sleeve 6 of anelastic material held by two rings 7 fastened to the tube 5. The tworings 7 have an inside diameter equal to that of the tube ll. The insidediameter of the sleeve 6 is less than that of the spear 2 which is to beforce-fitted. Once fitted, the spear is held in the gun by the elasticforce of the sleeve 6. The sleeve 6 together with the tube 5 defines anannular space 8. This space communicates via the orifice 9 through thevalve 10 with the compressed-gas tank 11. It also communicates via thechannel 12 with the outside through a nozzle 113 which is closed by avalve M. The valve 14 is held closed by the spring 15 housed in thehandle of the gun. The valve 14 opens automatically when the pressure inthe enclosure exceeds a limit value. The opening of the valve 14 can becontrolled by the hunter by means of the trigger 16 in order todischarge the spear.

The annular enclosure 8 communicates via channels 17 with the reservechamber 18 located at the rear of the sleeve 6. These channels areequipped with nonreturn valves 19.

The rear end of the arrow is held in the thrust chamber 20 which isseparated from the reserve chamber by a sealing ring 24. The sealingring 24 is housed in a groove cut in the part 21 screwed into the tube5. The

part 22 which is screwed into the thrust chamber 20.

The rear end of the gun is closed by a threaded plug 23. A floatingvalve is arranged at the rear of the thrust chamber, the head 26 beingplaced in the chamber 20. This valve is extended by a rod 27 and by ashank 28 which is housed in a cavity provided in the plug 23. Channels25 pass from one end of the plug 23 to the other.

When the plug 23 is screwed in entirely, it rests against the shank 28of the valve and the valve is maintained open. This is the safetyposition.

Upon unscrewing the plug 23, the floating valve 26 is freed.

Before introducing the arrow into the gun, the hunter screws in the plug23. When he introduces the spear, the water contained in the thrustchamber is discharged through the channels 25. When the hunter wishes tocock the gun, he opens the valve 10 for a certain period of time whileleaving the plug 23 screwed in. If the sealing ring 24 is damaged, thereis a leak of gas to the rear which warns the hunter.

Before starting to hunt, the hunter unscrews the plug 23. The valve 26is then freed. At the time of the departure of the spear, as long itsrear end has not passes the sealing ring 24, the valve 26 remains open,which avoids the chamber 20 being placed under vacuum. As soon as therear end of the arrowhas passed the sealing ring 24, the chamber 20 isunder pressure and the valve 26 closes, which avoids losses ofcompressed gas.

The operation of the gun is as follows. The hunter introduces the spearinto the gun through the barrel, forcing it in order to overcome theelastic force of the sleeve 6.

In order to cock the gun, the hunter opens the valve 10. The pressure isbuilt up in the annular space 8 and in the reserve chamber 18. Thehunter again closes the valve 10. The pressure in the space 8 maintainsthe sleeve applied with force against the arrow and the sleeve serves astight joint between the reserve chamber 18 and the barrel.

part 21 defines the In order to effect the departure of the arrow, thehunter presses against the trigger 16 and causes the decompression ofthe annular space 8. The compressed gas contained in the reserve chamber18 escapes, passing between the sleeve 6 and the spear, and it deformsthe sleeve 6. The water contained in the barrel is expelled and itpushes the slide 3 which causes the ejection of the spear. When the rearend of the spear has passed the sealing ring 24, it is subjected to thethrust resulting from the expansion of the gas contained in the reservechamber.

I claim:

1. A compressed-gas gun for propelling a spear under water whichcomprises:

a body;

barrel means mounted to one end of said body, said barrel and body beingadapted to receive the shaft of a spear;

compressed-gas storage means mounted to said body;

valve means fluidly connecting said storage means with the interior ofsaid body;

said body having interiorly from rear to front, a first chamber havingsealing means adapted to receive in gas tight relationship the end of aspear shaft, a compressed-gas reserve chamber forwardly of said sealingmeans, and a coaxially mounted elastic sleeve having an interiordiameter of a size to grip the shaft of a spear;

said barrel slidably supporting adjacent its front end a tubular slidemeans adapted to engage the end of a spear to partially eject the spear;

stop means on the end of said barrel to limit the forward movement ofsaid tubular slide means; and

trigger means mounted to said body to release said spear.

2. A gun according to claim 1, wherein said sleeve and said body definean annular chamber in fluid communication with said compressed-gasstorage means, and said body includes means for communicating saidannular chamber with the exterior of said gun.

3. A gun according to claim 2, wherein said communicating meanscomprises a channel normally closed by a calibrated valve and beingopenable by said trigger means to cause the release of a spear.

4. A gun according to claim 2, wherein non-return valves are positionedbetween said annular chamber and said reserve chamber, said non-returnvalves permitting fluid flow from said annular chamber to said reserve5. A gun according to claim 1, wherein said sealing means comprises asealing ring cooperative with the shaft of a spear to seal said firstchamber from said reserve chamber; and manually-operable floating valvemeans within said first chamber rearwardly of said sealing means.

6. A gun according to claim 5, which further includes a plug threaded inthe rear end of said body in such manner as to permit selectiveinsertion thereof, said plug defining at least one orifice extendingtherethrough and a cavity adapted to receive a guide rod of saidfloating valve means, a wall of said cavity being dimensioned to engagesaid guide rod when said plug is fully inserted to maintain saidfloating valve means in opened position.

UHILLU DLALIJD Iltllbfil urrlun CERTIFICATE OF CORRECTION Patent No.3,735,747 Dated y 29, 1973 Inventor(s) Jean Barjav el It is certifiedthe}: error appears in the above-identified patent "and that saidLetters Patent are hereby corrected as shown below:

Col. 4, line 16, a fter "serve" add chamber.-L

Signed and sealed this 201; day of November 1973.

(SEAL) Attest: EDWARD MaFIiETCHERi-J'R. RENE n C'IIEGTMEYER AttetihgGffieeic Acting Cbiiihiissibher of Patents foRM pooso uo-ss) USCOMM-OCeven-was

1. A compressed-gas gun for propelling a spear under water whichcomprises: a body; barrel means mounted to one end of said body, saidbarrel and body being adapted to receive the shaft of a spear;compressed-gas storage means mounted to said body; valve means fluidlyconnecting said storage means with the interior of said body; said bodyhaving interiorly from rear to front, a first chamber having sealingmeans adapted to receive in gas tight relationship the end of a spearshaft, a compressed-gas reserve chamber forwardly of said sealing means,and a coaxially mounted elastic sleeve having an interior diameter of asize to grip the shaft of a spear; said barrel slidably supportingadjacent its front end a tubular slide means adapted to engage the endof a spear to partially eject the spear; stop means on the end of saidbarrel to limit the forward movement of said tubular slide means; andtrigger means mounted to said body to release said spear.
 2. A gunaccording to claim 1, wherein said sleeve and said body define anannular chamber in fluid communication with said compressed-gas storagemeans, and said body includes means for communicating said annularchamber with the exterior of said gun.
 3. A gun according to claim 2,wherein said communicating means comprises a channel normally closed bya calibrated valve and being openable by said trigger means to cause therelease of a spear.
 4. A gun according to claim 2, wherein non-returnvalves are positioned between said annular chamber and said reservechamber, said non-return valves permitting fluid flow from said annularchamber to said reserve chamber.
 5. A gun according to claim 1, whereinsaid sealing means comprises a sealing ring cooperative with the shaftof a spear to seal said first chamber from said reserve chamber; andmanually-operable floating valve means within said first chamberrearwardly of said sealing means.
 6. A gun according to claim 5, whichfurther includes a plug threaded in the rear end of said body in suchmanner as to permit selective insertion thereof, said plug defining atleast one orifice extending therethrough and a cavity adapted to receivea guide rod of said floating valve means, a wall of said cavity beingdimensioned to engage said guide rod when said plug is fully inserted tomaintain said floating valve means in opened position.